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Nerve injuries requiring surgery are a significant problem without good clinical alternatives to the autograft. Tissue engineering strategies are critically needed to provide an alternative. In this study, we utilized aligned nanofibers that were click-modified with the bioactive peptide RGD for rat sciatic nerve repair. Empty conduits or conduits filled with either non-functionalized aligned nanofibers or RGD-functionalized aligned nanofibers were used to repair a 13 mm gap in the rat sciatic nerve of animals for six weeks. The aligned nanofibers encouraged cell infiltration and nerve repair as shown by histological analysis. RGD-functionalized nanofibers reduced muscle atrophy. During the six weeks of recovery, the animals were subjected to motor and sensory tests. Sensory recovery was improved in the RGD-functionalized nanofiber group by week 4, while other groups needed six weeks to show improvement after injury. Thus, the use of functionalized nanofibers provides cues that aid in in vivo nerve repair and should be considered as a future repair strategy.

Purpose  The current study compares the strength of a previously studied technique for flexor tendon repair with barbed sutures to an experimental approach that aligns all the barbs to oppose distraction. Methods  Twelve flexor tendons from cadaveric specimens were mechanically tested following repair of simulated zone II tendon injuries. Two repair techniques utilizing barbed sutures were studied: the Marrero-Amadeo four-core barbed suture approach and the experimental configuration with all barbs on four cores opposing distraction. Maximum applied load at failure, that is, ultimate load, and 2-mm gap force were compared between the two repair techniques, both as raw values and after normalization to cross-sectional area of the intact tendon. Statistical testing was performed using t -tests and Mann-Whitney U -tests, where appropriate, with a significance level of 0.05. Results  The ultimate loads, raw (58.2 N) and normalized (4.8 N/mm 2 ), were significantly larger for the Marrero-Amadeo repair than the proposed experimental approach (35.6 N and 2.7 N/mm 2 ; p  < 0.05). No significant differences were identified for 2-mm gap force. Conclusion  The innovation of suturing to align all barbs to oppose distraction does not improve strength of the repaired tendon. The Marrero-Amadeo technique was found to have superior strength for use in traumatic zone II flexor tendon injuries.

The scaphoid is the most commonly fractured carpal bone of the wrist. It is an unusual carpal bone in that it bridges both the proximal and the distal rows; this subjects it to continuous shearing and bending forces. Approximately 80% of the scaphoid is covered by cartilage, which limits its ligamentous attachment and vascular supply. Most scaphoid fractures occur at the waist. Acute stable fractures or incomplete fractures of the scaphoid may be treated nonsurgically; a high rate of union can be expected. However, there is considerable debate about the type of immobilization needed. Although closed treatment of stable wrist fractures of the scaphoid achieve a high rate of healing, prolonged cast immobilization may lead to complications, including muscle atrophy, possible joint contracture, and disuse osteopenia. Because of this, internal fixation of minimally displaced fractures of the scaphoid has recently become popular. There is consensus in the literature that nonunion of the scaphoid and proximal pole fractures should be treated surgically. In the past several decades, percutaneous arthroscopic techniques of scaphoid stabilization, which minimize surgical morbidity, have become popular. There also has been a significant improvement in the management of difficult scaphoid nonunions, with or without deformity. Improved techniques include open and dorsal approaches and vascularized bone grafting of resistant scaphoid nonunions. Declining in popularity is the prolonged immobilization of unstable fractures when surgical stabilization may have been a better treatment option.